1. Field of the Invention
The present invention relates to a control loop bandwidth adjusting method for adjusting a control loop bandwidth of an optical reproducing device, and more particularly to a data signal processing circuit for processing the data signal with the control loop bandwidth.
2. Description of the Prior Art
Please refer to FIG. 1. FIG. 1 is a schematic diagram of an optical reproducing device 10 that reads a data signal from an optical recording medium 12 according to the prior art. When the optical reproducing device 10 reads the data signal from the optical recording medium 12, an optical pickup head 14 uses a laser beam 16 to focus on the optical recording medium 12 in a predetermined distance and to write or read the corresponding optical data into or from the optical recording medium 12.
Generally, for writing or reproducing the optical data completely, a data signal processing circuit 18 is used for assisting in processing the data signal. The data signal processing circuit 18 can be a servo control circuit, a data/clock recovery PLL, or a slicer. The data signal processing circuit 18 can be a servo control circuit for processing actuation control to the optical pickup head 14, a data/clock recovery PLL for synchronizing the data signal, or a slicer for slicing the data signal.
However, when the optical reproducing device 10 reads the defect data signal from the optical recording medium 12, the defect data signal will generate a corresponding defect data signal, and the defect data signal will cause the optical reproducing device 10 to read incorrect data signals, then the data signal processing circuit 18 will perform an incorrect process.